AfA480: 2004 Climate Change Fluvial Flood Depth Grids for England

England-wide modelled fluvial flood depth data for a 1% annual chance flood event, incorporating a 20% increase in peak flows as a climate change sensitivity analysis. The data was produced in 2004 using the JFlow two-dimensional hydrodynamic model on a 5x5 meter grid to fill gaps in detailed local modelling for spatial planning. This dataset is available in 100x100 km tiles corresponding to Ordnance Survey National Grid references, such as SZ and SP.

Use Cases

• High-level flood zone definition for spatial planning based on generalized 2004 modelling.
• Sensitivity analysis of potential climate change impacts on fluvial flooding using a 20% peak flow increase scenario.
• Identifying areas for further detailed flood risk assessment where local modelling is absent.

Strengths

• Provides national coverage for England, filling a historical gap in detailed local data from 2004.
• Uses a specific, high-resolution 5x5 meter grid generated by the JFlow hydrodynamic model.
• Incorporates a defined climate change scenario (20% increase in peak flows) for sensitivity analysis.

Limitations

• The dataset has not been updated since its creation in 2004, and climate change allowances have since changed.
• Explicitly not suitable for property-level assessment, detailed decision-making, or site-specific flood risk assessments.
• Metadata for size, row count, license, and specific columns is missing or listed as unknown across all sources.

Provenance

Source

Government Digital Service (from eu_open_data platform), likely originating from the UK Environment Agency's Approval for Access product AfA480.

Collection Method

Produced as a by-product of a 2004 generalised modelling project using the JFlow two-dimensional hydrodynamic model.

Time Range

2004

Freshness

Metadata last updated July 6, 2026, but the underlying data is from 2004 and has not been revised.

Geography

England, delivered in 100x100 km tiles (e.g., Ordnance Survey grid references SZ, SP).